Pivot release for x-ray examination table



Dec. 13, 1955 R. J. WAGNER ETAL 2,726,909

PIVOT RELEASE FOR X-RAY EXAMINATION TABLE Filed 001:. 28, 1954 WlTNESSESI INVENTORS Robert J.Wogner 54 W/ ond Eugene P. Thomcs.

M aw. I g 5m ATTORNEY United States Patent PIVOT RELEASE FQrlzgi-RAY EXAMINATION Application October 28, 1954, Serial No. 465,166

3 Claims. (Cl. 311-6) Our invention relates to tiltable X-ray examination tables and in particular to the provision of releasable bearings at opposite ends of the table top about which it may be tilted through ninety degrees in either direction from the horizontal.

In modern X-ray examination, the patient lies on a table having a top which may be tilted up to ninety degrees in either direction from the horizontal, the X-ray tube being supported from the table top and projecting its beam always in a direction normal thereto. The patient mounts the table in its horizontal position, and a motordrive then tilts the table in the desired direction. For this purpose, a pair of pivots are provided near each end of the table top and the base is provided with releasable bearings near each of its ends, the appropriate one of which is moved into engagement with the pivot about which it is desired that the top shall tilt, the other pivot remaining free from engagement with its associated hearing. It is, of course, necessary to avoid disaster that, once the table top has departed from horizontal position, the bearing about which tilt has started shall not be released from engaging its pivot until the table top has been returned to horizontal position. Our invention to lates to an improved mechanical arrangement for provid ing pivots and bearings for the table top, and for automatically locking each bearing in engagement with the appropriate pivot when tilt starts, and holding it so locked until the table is returned to horizontal position. This we accomplish by providing a pivoted plate which bears against the rim of a sprocket driving the tilt-linkage and is prevented from movingto engage or disengage the pivot bearings except at times when the sprocket holds the table in its horizontal position.

One object of our invention is accordingly to provide a new and improved tiltable-top X-ray or other examination table.

Another object is to provide a novel and improved mechanical arrangement for automatically tilting a movable member about either one of two pivot axes spaced along its length, locking a bearing member into engagement with the appropriate pivot and retaining said bearing engaged and the pivot and hearing at the other axis disengaged, until the member returns to its starting position.

Another object is to provide a tiltable-top X-ray table with a reversible motor-driven linkage and releasable pivot-bearings near its opposed ends in which a drivewheel in the linkage, when departing from zero-tilt, moves a pivoted camming member to engage one of said pivot bearings and holds it so engaged by control of said camming member with a run on the drive-wheel until the table top returns to zero tilt.

Other objects of our invention will become apparent upon reading the following description taken in connection with the drawings, in which:

Fig. l is a schematic view in elevation partly broken away of an examination table embodying the principles of our invention;

Fig. 2 is a detail view of certain portions of the mechaice nism of Fig. 1 when the table top is in its zero tilt or horizontal position; 7

Fig. 3 is a view similar to Fig. 2 when the table top is tilted in one direction from horizontal; and

Fig. 4 is a view similar to Fig, 2 when the table top is tilted in the other direction from horizontal.

Referring in detail to the drawings, an examination table comprises a base 1 having a tiltable top 2 arranged to tilt through any angle up to ninety degrees about either one of pivots 3 and 4. The X-ray tube (not shown) is movably supported within the tiltable top 2 to project its beam substantially normal to the top 2 on which the patient undergoing examination is to be prostrate. Since the details of X-ray tubes and their support are well known in the art and do not specifically concern our present invention, it is believed that no further description of them is necessary here.

Tilting of the table top 2 is effected by a motor drive comprising a drive sprocket 5, chain 6, and driven sprocket 7, sometimes called a bull sprocket. The sprocket 7 turns on a shaft 8 supported on base 1 and carries a link 9 which is pivoted at its end (lower end in Fig. 1) to a second link 11 which is attached by a pivot 12 to the table top 2. When sprocket 7 turns on its axle, the links 9 and 11 push upward on the pivot 12 and so raise the mid-point of table top 2.

The bearings for the pivots 3 and 4 comprise semicircular hooks 13 and 14 pivoted at 15, 16 to base 1 and interconnected by a pivoted link bar 17 of such length that when one hook (say 13) fully engages its associated pivot, the other hook (as 14) clears its associated pivot (4) so that the latter may move upward without interference as the table top 2 is tilted about pivot 3 by the upward thrust of linkage 9, 11 on pivot 12. When it is desired to tilt the table top in the opposite direction, link bar 17 is moved to disengage hook 113 from pivot 3 and engage hook 14 with pivot 4.

It is, of course, absolutely necessary that, once the table top has left its horizontal position, the link bar 17 and the hook 13 or 14 which engages the pivot 3 or 4 about which the table top 2 has started to tilt shall be locked in position, and a principal novel feature of our invention is the arrangement for insuring this which is shown in clearer detail in Figs. 2, 3 and 4.

The locking arrangement comprises a plate 21 which turns on a pivot 22 set in base 1, and is provided with a hardened steel pin 23 which engages a slot 24 in link bar 17. As plate 21 turns on pivot 22 from its midposition, it displaces link bar 17 to the right or left and correspondingly engages either hook 14 or book 13 with its associated pivot 4 or 3.

The bull sprocket 7 is provided on its side adjacent link bar 17 with a circular ledge or rim 25 having a depression 26 in radial alignment with a pin 27. The pivoted plate 21 has two edges 28, 29 shaped respectively to ride against rim 25 when the plate 21 has been turned about pivot 22 to one of its two extreme positions wherein pin 23 has moved link bar 17 to its end position locking hook 14 into engagement with pivot 4 or to its end position locking hook 13 into engagement with pivot 3. That is to say, hook 14 is held in engagement with pivot 4 as long as edge 28 engages rim 25; and hook 13 is maintained in engagement with pivot 3 as long as edge 29 rides on rim 25.

Pivoted plate 21 is provided with a pair of hardened steel pins 31, 32 symmetrically positioned relative to pivot 22 so that when pin 27 is radially aligned with pivot 22 it holds pivoted plate 21 in its mid-position in which pin 23 and slot 24 likewise hold link bar 17 in its mid-position. Linkage 9, 11 is arranged to be at that time in the position at which table top 2 is horizontal. The depression 26 in rim 25 of bull sprocket 7 leaves room for the portion of pivot plate 21 between the adjacent ends of edges 28 and 29.

The mode of operation of our locking device will now be readily seen. To begin with, table top '2 is horizontal, and our locking means is in the position shown in Fig. 2. If the radiologist starts drive sprocket S in clockwise rotation, the pin 27 on bull sprocket 7 pushes against pin 32 turning pivot plate 21 counterclockwise about its pivot 22; pin 23 pushes slot 24 and link bar 17 to the left causing hook 14 to engage pivot 4. Further, clockwise rotation of bull sprocket 7 causes linkage 911 to tilt table top 2 about pivot 4, and also causes the edge 28 of pivot plate 21 to ride in engagement with rim 25 on bull sprocket (as shown in Fig. 4) until table top 2 reaches the angle of tilt chosen by the radiologist. Until the latter returns the apparatus to the untilted position,

engagement of edge 28 with rim 25, min Fig. 4, keeps hook 1 locked in engagement with pivot 4.

, When the radiologist drives bull sprocket 7 in counterclockwise rotation, pin 27 cams against pin 31 of pivot plate 21 to turn it clockwise to the position shown in Fig. 3, and engagement of edge 29 with rim holds the link bar displaced to the right so that hook 13 is held in engagement with pivot 3, while linkage 9--11 is tilting table top 2 about the latter.

The mechanism which we have devised thus automatically locks the bearing on which table top 2 turns whenever it is outside its horizontal position.

We claim as our invention:

1. In combination with a table having a top tiltable about either one of two pivot members, a table tilting mechanism including a rotatable member for applying force to tilt said top, a pair of releasable bearings, with each of said bearings being movable into and out of association with a'diiferent one of said pivot members, a link member movable into a pair of locking locations to lock said hearings in their respective associated positions when said top is tilted about either one of said two pivot members, and locking means for said link member comprising a circular rim for said rotatable member, a locking piece pivoted relative to said table and arranged to move said link member into one or the other of said two locations depending upon whether the locking piece is rotated about its pivot in a clockwise or a counterclockwise direction, said locking piece including a pair of bearing edges which respectively engage said rim when said link member is positioned to associate one of said bearings with one of said pivot members, and a control member for pivoting said locking piece in respectively a 4 7 one or the other of said directionsabout its pivot when said top moves from its untilted position.

2. In combination with a table having a top tiltable about either one of two pivot members, table tilting means including a rotatable member for applying force to tilt said top, a pair of releasable bearings, each of said bearings being respectively movable into and out of association with a diiferent one of said pivot members, a link means to so move said hearings in their respective associated positions dependent upon said top being tilted about either one of said two pivot members, and locking means for said link means comprising a circular rim for said rotatable member, a locking piece pivoted relative to said table and arranged to move said linkmeans when said locking piece is rotated about its pivot, said locking piece including a pair of bearing edges which respectively engage said rim when said link means is positioned to associate one of said bearings with one of said pivot members, and a gap in said rim allowing disengagement thereef from both said bearing edges .when said top is in its untilted position. i

3. In combination with a table having a top tiltable about either one of two pivot members, table tilting means including a rotatable member for applying force to tilt said top, a pair of releasable bearings respectively movable into and out of association with a different one of said pivot members by a link means to lock said bearings in their respective associated positions when said top is tilted about either one of said two pivot members, and locking means for said link means comprising a circular rim for said rotatable member, a locking piece pivoted relative to said table and arranged to move said linkmeans when said locking piece is rotated about its pivot, a pair of bearing edges which'respectively engage said rim when said link means is positioned to associate one of said bearings with one of said pivot members, a gap in said rim allowing disengagement thereof from both said bearing edges when said top is in its untilted position, and a projection on said rotatable member positioned to turn said locking piece about its pivot when said top moves from its untilted position.

References Cited in the file of this patent UNITED STATES PATENTS 2,222,888 Haupt Nov.'26, 1940 2,379,071 Faust et a1. June 26, 1945 2,693,399 Vaughn Nov.'2, 1954 2,701,744 Koerner et a1 Feb. 8, 1955 

